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Outsmarted by nooptropics? An investigation into the thermal degradation of modafinil, modafinic acid, adrafinil, CRL-40,940 and CRL-40,941 in the GC injector: formation of 1,1,2,2-tetraphenylethane and its tetra fluoro analog.
Full text link2-[(Diphenylmethyl)sulfinyl]acetamide (modafinil) is commonly prescribed for the treatment of narcolepsy and increasing popularity and off-label use as a cognitive enhancer resulted in a reputation as an intelligence boosting ‘wonder drug’. Common alternatives available from online shops and other retail outlets include 2-[(diphenylmethyl)sulfinyl]-N-hydroxyacetamide (adrafinil), 2-{[bis(4- fluorophenyl)methyl]sulfinyl}acetamide (CRL-40,940), 2-{[bis(4- fluorophenyl)methyl]sulfinyl}-N-hydroxyacetamide (CRL-40,941) and N-methyl-4,4-difluoro-modafinil (modafiendz), respectively. Gas chromatography mass spectrometry (GC-MS) is a common tool used in forensic and clinical analysis but there is a potential for inducing analysis-related ambiguities. This study reports on the thermal degradation of modafinil, modafinic acid, adrafinil, CRL-40,940 and CRL- 40,941 due to exposure to the heated GC injection port dissolved in a variety of solvents. Key degradation products common to modafinil, modafinic acid, adrafinil analysis included diphenylmethanol and 1,1,2,2-tetraphenylethane (TPE), the latter of which was verified by its synthesis and characterization by x-ray crystallography. The investigated compounds were also characterized by 1H and 13C NMR. Diphenylmethane and thiobenzophenone were also identified in some instances. TPE formation was suggested to involve the generation of a benzhydrylium ion and its reaction with the sulfoxide oxygen of the parent compound to give an oxysulfonium intermediate. Correspondingly, the fluorinated TPE analog was formed during heat-induced degradation of modafiendz, CRL-40,940 and CRL-40,941, respectively. When a mixture of modafinil (non-fluorinated) and modafiendz (fluorinated) were subjected to GC analysis, 4,4'-(2,2-diphenylethane-1,1-diyl)bis(fluorobenzene) was detected as a third cross reaction product in addition to the two expected TPE analogs. These observations served as a reminder that the seemingly straightforward implementation of GC-MS analysis can lead to challenges during routine analysis
Endophytic fungi of Tectona grandis L. (Teak).
No full textTaxonomic diversity, biology and ecological aspects of fungal endophytes of Tectona grandis (teak) from Chiang Mai Province, Thailand were investigated. It was found that the endophyte assemblages of mature leaves sampled from natural forest and plantation teak were not significantly different. Members of the Xylariaceae, especially Daldinia eschscholzii, Nemania subannulata, Hypoxylon haematostroma and Xylaria cubensis were frequent isolates. Widely reported endophytic fungi such as Phomopsis, Colletotrichum, Cladosporium and Fusarium were also isolated. There is little evidence to support host specificity for the majority of the isolates. Differences in endophyte assemblages between young and mature leaves were shown to occur with a much lower infection percentage in the young leaves. Species of Phomopsis and Colletotrichum were dominant in the young leaves but members of the Xylariaceae dominated in mature leaves. This pattern was the same for both natural forest and plantation samples. However comparison of taxa isolated from leaf lamina, midrib and veins gave conflicting results. Samples from mature leaves from natural forest trees exhibited little variation with greater variation in taxa recovered being found to occur between sampling years than between position of isolation from the leaf. In plantation leaves, although the results were similar to those from natural forest tree leaves for two of the years sampled, in 1997 the overall recovery rate was highest for the lamina, followed by veins and then the midrib. There was no evidence obtained to link individual taxa with specific regions of the leaf. It is now possible to devise a sampling strategy to obtain suitable diversity of endophytic isolates from teak leaves for industrial screening of these fungi. Techniques were developed to overcome current problems of identification of xylariaceous endophytes in the absence of their teleomorph. Inoculation of suitable woody substrata combined with selective incubation was used to induce teleomorph formation in many of the isolates and this together with chemical profiling enabled identification to species of many of these isolates. Rates of development of specific species were obtained and differences in environmental conditions necessary for development of teleomorphs to maturity were noted for members of different genera. Thus species of Daldinia and Hypoxylon required drier conditions than species of Xylaria and Nemania which only developed under wet shaded conditions. Xylariaceae from the natural forest, plantation, and forest surrounding the plantation were surveyed and a number of the Xylariaceae recovered as endophytes were found to be new to science, new records for Thailand or were recorded as endophytes for the first time
The effects of stress incontinence on women and its management by health care professionals, during pregnancy and following delivery.
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Early observations of the nearby type Ia supernova SN 2015F
No full textWe present photometry and time-series spectroscopy of the nearby type Ia supernova (SN Ia) SN 2015F over days to days relative to maximum light, obtained as part of the Public ESO Spectroscopic Survey of Transient Objects (PESSTO). SN 2015F is a slightly sub-luminous SN Ia with a decline rate of mag, placing it in the region between normal and SN 1991bg-like events. Our densely-sampled photometric data place tight constraints on the epoch of first light and form of the early-time light curve. The spectra exhibit photospheric C II absorption until days, and high-velocity Ca II is particularly strong at km s, suggesting mixing in the outermost layers of the SN ejecta. Although unusual in SN Ia spectra, including V II in the modelling significantly improves the spectral fits. Intriguingly, we detect an absorption feature at 6800 \AA\ that persists until maximum light. Our favoured explanation for this line is photospheric Al II, which has never been claimed before in SNe Ia, although detached high-velocity C II material could also be responsible. In both cases the absorbing material seems to be confined to a relatively narrow region in velocity space. The nucleosynthesis of detectable amounts of Al II would argue against a low-metallicity white dwarf progenitor. We also show that this 6800 \AA\ feature is weakly present in other normal SN Ia events, and common in the SN 1991bg-like sub-class
Survey: Development and analysis of a games-based crisis scenario generation system
No full textCrisis is an infrequent and unpredictable event which is challenging to prepare and resolve. Serious-game approach proved to provide potential support in training and simulating event of real-world crisis situation to different stakeholders. Yet in practice, the approach meets with difficulty on how to setup and utilize different core components such as asset management, crisis scenario generation, agent simulation, real-world constraints, and the evaluation process to yield beneficial information upon running the system. To address this issue, the key question is what can be done to propose a general crisis game-based framework providing necessary core components while generating evaluation result yielding potential analytical data for a crisis management process. Therefore, in this paper, we aim to review and consolidate the existing research on scenario generation techniques and related crisis simulation framework, then to propose novel solution to combine both processes and to derive a desirable scenario content which is also being validated in the simulation framework based on the JADE multi-agent architecture. © Springer International Publishing Switzerland 2016
Generating a Novel Scene-Graph for a Modern GIS Rendering Framework
Full text linkWithin this paper we discuss and present a novel modern 3D Geographical Information System (GIS) framework Project-Vision-Support (PVS). The framework is capable of processing large amounts of geo-spatial data to procedurally extract, extrapolate, and infer properties to create realistic real-world 3D virtual urban environments. The paper focuses on the generation of a novel scene-graph structure used in a number of algorithms and novel procedures for the increased rendering speeds of large virtual scenes and the increased processing capabilities as well as ease of use to manipulate a worlds worth of data. The scene-graph structure, made of two sections, depicts the spatial boundaries of the UKs Ordnance Survey (OS) scheme down to 1km2. Each 1km2 node contains the second section of the scene-graph structure, generated from the OpenStreetMap (OSM) classifications; involving buildings, highways, amenities, boundaries, and terrain. Leaf nodes contain the model mesh data. Generation of the spatial scene-graph for the UK takes 7.99 seconds for 6,313,150 nodes. The scene-graph structure allows for fast dispersal of render states, as well as scene manipulation by pre-categorising the data into branches of the scene-graph structure. Searching a node by name is evaluated using depth-first-search and breadth-first-search giving 0.000186 and 0.036914 seconds respectively within a scene-graph of 3257 nodes
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